The past 25 years of research under this Center grant have solidified the observations 1) that under hypoxic conditions, many processes of wound healing cannot proceed normally, particularly resistance to infection, collagen synthesis, angiogenesis, and inflammation; 2) that these processes, in fact, work more efficiently at supraphysiologic oxygen concentrations; and 3) that hypoxic conditions are the norm in injured tissue and in trauma patients. These observations lead inescapably to the conclusion that one of the most critical aspects of the care of traumatized patients is maintenance of oxygen delivery to injured tissues. This requires high flow of blood at high PO2 but not necessarily high oxygen content. Physician estimates of peripheral perfusion are usually inaccurate (usually overestimates); therefore, this goal cannot be achieved unless tissue oxygen is measured. The aim of the current proposal is to convert tissue oximetry from a research tool to a clinical monitor, by identifying means to remove obstacles to perfusion, and by demonstrating that use of these means combined with PO2 monitoring in the ICU setting leads to improved patient outcome.